* {
    margin: 0;
    padding: 0;
}
/* 将3d视图浮动起来 */
#threeMain {
    position: fixed;
    top: 0;
    left: 0;
}
body {
    overflow: hidden;
   
    background: linear-gradient(90deg, #02a0ff, red);
    

}
#threeMain{
    background: transparent;
}